FORT COLLINS, Colo. -- Undercover investigators using text messages to meet with a couple claiming to seek sex with a child learned that the two conspired to rob a pedophile and kidnap his daughter, according to their arrest affidavits.

Dustin Canup, 20, and Sareena Morrison, 18, both of Loveland, Colo., were arrested Friday at the Hi-Way Motel in Loveland, where they'd planned to meet who they thought was a man and his 6-year-old daughter to perform sex acts. Loveland Police detectives, who'd rented the room after finding Morrison through a citizen's tip, found handcuffs and a 12-inch knife on Canup.

"Morrison and Canup admitted to planning to meet (men found through a pornographic website) and extort them for money or take their money by force if necessary when they met," according to the affidavits. "(The two) admitted that they were planning on kidnapping this 6-year-old girl from Loveland, keeping her, and raising her as their own daughter."

The couple told police Canup had lost his job, they were seeking money, and they had no intention of having sex with children.

A tipster had reported Morrison's cellphone number to police because it was connected with someone claiming online to be a 15-year-old girl offering herself for sex.

The couple told police they would monitor the pornographic website to find men claiming a desire for Morrison to engage in sex acts with children, according to the affidavits. They also admitted they had set up other meetings, but it appears this meeting was their first.

Loveland police Sgt. Mike Halloran said in an email that he doesn't know whether there was an actual man with a 6-year-old daughter involved with the case, but there are continuing investigations which he declined to comment on.

Canup and Morrison were booked into Larimer County Jail on possible charges of conspiracy to commit kidnapping, extortion and robbery. Neither has a previous criminal record, according to Colorado court records.

Canup is being held on $100,000 bond, and Morrison is being held on a $75,000 bond.